1. Field of the Invention
The present invention relates to a novel .alpha.-1,6-glucosidase and a process for producing the same, and more particularly to a novel .alpha.-1,6-glucosidase obtained from the culture of a novel strain of Bacillus sectorramus producing an .alpha.-1,6-glucosidase having an optimum pH in the vicinity of 5.0 to 5.5 and an optimum temperature in the vicinity of 55.degree. C., and a process for producing said novel .alpha.-1,6-glucosidase which comprises collecting .alpha.-1,6`-glucosidase from the culture of said strain.
.alpha.-1,6-glucosidase is an enzyme capable of acting on an .alpha.-1,6-glucoside bond in starch or the like to produce straight chain amylose, and is widely employed in the saccharification industry for the production of maltose, glucose, and high fructose corn syrup (HFCS).
2. Related Background Art
.alpha.-1,6-glucosidase has long been found in the higher plants and yeast of microorganisms, and has recently reported to be produced by various bacteria, such as those of Aerobactor aerogenes, Escherichia intermedia, Pseudomonas amyloderamosa, Streptococcus mites, Cytophaga, Streptomyces, and Flavochromogenes.
On the other hand, among .alpha.-1,6-glucosidases produced by the Bacillus strains, there are already known those of Bacillus cereus (IFO 300), Bacillus fermus (IFO 3330), Bacillus acidopullulyticus etc.
Most of the known .alpha.-1,6-glucosidases have neutral or weakly alkaline optimum pH values and are not suitable for use in the saccharification industry, where the saccharification is conducted in acidic conditions.
As .alpha.-1,6-glucosidases having an acidic optimum pH are known to be produced by Pseudomonas amyloderamosa and Bacillus acidopullulyticus, the former is impractical for use due to poor temperature resistance, while the latter is unfavorable economically, requiring a long culture period of 60-73 hours for production.